Galapagos frolic

This week, a glaring omission is corrected. The Science Show goes to the Galapagos Islands. Despite being on holidays, Robyn Williams has his trusty recorder and microphone on hand as he takes a boat trip between the islands. Naturalists explain the habits of fish, reptiles and birds and we visit the sites where Charles Darwin was so inspired by what he saw, that it led to the development of his theory of natural selection, explaining evolution and the diversity of life on Earth.

Supporting Information

Music used:Excerpts from Australia and all that Jazz Composed by John Sangster, featuring John Sangster, Errol Buddle, Don Burrows,Tony Buchanan, George Golla, Graeme Lyall, Derek Fairbrass and Ed Gaston.Cherry Pie Records 1971 and 1976

Transcript

Robyn Williams:The Science Show this week comes from the Galapagos Islands, an hour's flight from the coast of continental Ecuador, it's right on the equator. And I'm here on a personal trip, so no budgets were harmed in the making of this program. And if you saw David Attenborough's magnificent Galapagos series, then this is a follow-up, one that you might do, being escorted by naturalists from Ecuador, as access to these famous islands is strictly controlled. You don't just wander about on your own. I'm on a big ship. But we get to each contrasting island by means of a Zodiac, a rubber boat led by an expert guide. So let's land and see what's there.

Could you tell me your name?

Juan Carlos: Juan Amia, Juan Carlos.

Robyn Williams: And you're from?

Juan Carlos: I am from Ecuador, from Guayaquil.

Robyn Williams: Guayaquil, which is just on the…

Juan Carlos: Guayaquil is the main port in Ecuador.

Robyn Williams: And we are on the island here in the Galapagos of Santiago.

Juan Carlos: Yes.

Robyn Williams: And did Darwin actually come here to where we are standing?

Juan Carlos: Walking around here into all of these areas, yes, he explored it for around five, seven days, but he has been there in Galapagos around over a month.

Robyn Williams: And so that was about 1835.

Juan Carlos: Just a moment please. Let me show you please something very important around here. We have two seasons on the island, between January and to April/May, that is the hot moment, the rainy season in the island. Why? Because the Panama current arrives from the north. The Panama currents is two warm currents, and in that moment it is raining for three or four months, and it could be raining for two or three hours during the day. But that is the best time for Darwin finches, for mockingbirds, because they find a lot of humidity, a lot of insects. And indeed, they have a lot of berries on Galapagos Island. And that moment, February/March, all of this area will be very, very green and humid.

But the second season, from May to December, that is the cool season in Galapagos Island because the Humboldt current arrives from the south. The Humboldt current is very chilly, very chilly water, that is the best moment for the marine life. Sea lions mating all year round. We have the whales, we have humpback whales, Minke whales, then we have the bottlenose dolphin approach, normally all year round, even orcas or killer whales.

But to July, August, September is the cool season on the island, this is the best time for swimming and snorkelling, it's too cold, right, but it's the best moment for the marine life, especially for blue footed boobies and Nazca boobies. And that is the moment, from May to December, they arrive, the waved albatrosses are nesting for seven, eight months in Espanola Island, the waved albatrosses, that's it. Any questions please?

Robyn Williams: This is the biggest island, one of the biggest islands?

Juan Carlos: No, the third one. The first one is Isabela, Santa Cruz, and then…

Robyn Williams: But this is a big one?

Juan Carlos: One of the big ones.

Robyn Williams: And when we went yesterday past…is it Daphne Island?

Juan Carlos: Daphne Island.

Robyn Williams: There are two scientists who…

Juan Carlos: Rosemary and Peter Grant.

Robyn Williams: And what they do there?

Juan Carlos: They work with Darwin finches.

Robyn Williams: They study the finches.

Juan Carlos: Yes, the evolution, they have the reproductions of the Darwin finches there.

Robyn Williams: And is it true they've been going there for about 20 years?

Juan Carlos: Yes, more or less, a lot of time.

Robyn Williams: And they actually stay on that tiny island?

Juan Carlos: Well, they have for each two years to spend several months in that area.

Robyn Williams: Work on those finches. And those two islands where the scientists live are so tiny, and they spend months there.

Now as we walk we see a sea lion mother suckling her calf, and then leaving.

Juan Carlos: They have…and this mummy…we have a low tide, and this mummy, she has the opportunity for fishing better, diving more. For that reason leaving alone for three or four hours, depending on the age of the baby. The baby looks like three or four months old. She is going to leave him alone for four or five hours more or less because she needs to fish, and at any moment came back and they find the babies in the same area. And barking, barking the mummy, barking for calling, at the same time complement with the smell. For that reason one of the rules is not to touch the animals.

Robyn Williams: But she is coming towards us.

Juan Carlos: Oh yes.

Robyn Williams: She wants to touch me.

Juan Carlos: Yes, it's looking. Like a social behaviour…

Robyn Williams: Hello there. You are about two metres away…

Juan Carlos: Waiting for mummy. She's confused, the baby's confused.

Robyn Williams: So mummy's fishing.

Juan Carlos: Yes, mummy's fishing at this moment.

Robyn Williams: May I just ask you, what's over there?

Juan Carlos: The marine iguanas. We have marine iguanas down there. Look at that one.

Robyn Williams: It's got a black hands holding onto the rock, and there's something crawling next to it, what is that?

Boy: A hermit crab.

Robyn Williams: That's a hermit crab. And the marine iguana, having been in the water, is now warming up again because they are cold-blooded. Is that right? They go out to sea and they nibble seaweed underwater because there's not enough on land. And this one is alone.

And what about all those very large rosy-coloured pink crabs?

Juan Carlos: They are Sally Lightfoot crabs, endemic species to the island. We are going to find them everywhere around the whole Galapagos Islands. Look at that, baby sea lions…

Robyn Williams: Now I'm just walking past a marine iguana. I'm getting so used to them. I mean, they are all over the place. I shouldn't be this close, I'm about one metre away. It has hardly given me a glance. I haven't seen them snort. They snort to get rid of the salt that they imbibe when they are down under the water eating seaweed. And over here we have a giant bird. Let me see if I can find Juan Carlos to find out what it is. It's something like more than a metre high.

Juan Carlos, we're about 20 metres from this huge bird that's at least a metre high, and it's grey, it's got black, brown feathers, and it's looking at us in a very kind of wise and very relaxed way. What is it?

Juan Carlos: This is a great blue heron, it's a permanent resident on the island, we call it, it's a native.

Robyn Williams: So this one is resident, it doesn't…

Juan Carlos: We call it a permanent resident on the island. We call it endemic because they have mating only here and they change something from the ancestor because no change, arrive 1,000 years…

Robyn Williams: Having been here all these years, have you got used to the Galapagos yet? Do you just take it for granted, do you just think, 'Oh yeah, here they are again'?

Juan Carlos: I enjoy the life, I've been living here for 20 years, I have been a naturalist for 12 years. I like to be here diving, walking, swimming, I enjoy the nature.

Robyn Williams: And when you go diving, have you been surrounded by sharks?

Juan Carlos: Right, I'm sure. That's amazing.

Robyn Williams: How many sharks have you been surrounded by at one time?

Juan Carlos: Well, I saw people diving, even with pictures, 100 of them around. Yes, that is scary.

Robyn Williams: 100? What sort of sharks?

Juan Carlos: I don't know…

Robyn Williams: Hammerhead?

Juan Carlos: Hammerhead is the most common, right, yes.

Robyn Williams: But they don't attack you?

Juan Carlos: Not yet.

Robyn Williams: You smell wrong.

Juan Carlos: [laughs] Oh yes!

Right, it's time for another eruption. Isabela, Darwin and Alcedo volcanoes, the three volcanoes on Galapagos Islands. That is Fernandina, that was the last one with volcanic activity. Even these islands 130 years ago more or less they have one big volcanic activity. This afternoon we are going to walk on the new lava flow. That is going to be exciting.

Robyn Williams: In the lava flow?

Juan Carlos: In the lava flow, right.

Robyn Williams: Won't that be a bit too hot?

Juan Carlos: Normally yes. I hope no!

Robyn Williams: That's challenging!

Well, this has been the first few minutes of me on a Galapagos island, and the first impressions are that you cannot believe how much wildlife there is just everywhere. If you walk too fast you find you might be stepping over a marine iguana. Just there, disguised on the black rock. And around the corner is yet another suckling mother sea lion with pup. And so many of these pink crabs everywhere. The birds hovering in the sky. I've got about 40 or 50 marine iguanas, some chasing each other or seeming to chase each other in a quite steady pace, and all over the black lava which is characteristic of these islands and, as you heard, volcanoes as far as the eye can see. And over my head comes one of those brown pelicans zooming past towards the horizon.

Monica Plaza: I'm Monica Plaza, I'm a Galapagos national park nationalist for 20 years, and at the moment I am a cruise director on this ship.

Robyn Williams: And as we look over there we can see a wonderful red beach with very high…I'd say mountains, yes, with cliffs eroded, and there are white spots on the cliff. What are they?

Monica Plaza: Guano. The guano is the seabird faeces, and you can tell it's a very popular rock with the seabirds. Probably guano from pelicans or blue-footed boobies.

Robyn Williams: And are there scientists working there virtually all the time on different islands?

Monica Plaza: Yes, most of the work is done in the fields, yes. There will be places where you can go as a volunteer, if you join one of those scientific groups going there.

Robyn Williams: Going back say 50, 60 years, is it the case that people from Ecuador were actually farming here on the islands?

Monica Plaza: They still are, yes. We have families, maybe four or five generations already from Ecuadorians that have been here, maybe more, because actually the islands were declared Ecuadorian in 1832, and you have people in San Cristobal from that long ago.

Robyn Williams: The farming of what?

Monica Plaza: We have cattle ranching mainly. But we do have also a group of…a fishing community as well, which is allowed here, maybe 1,000 families live on that, artisanal fishing, not industrial fishing.

Robyn Williams: Artisanal? What's the difference?

Monica Plaza: The difference is that we don't have these huge boats with factories where you put everything. We have seasons, we do it in a sustainable way. We have seasons for lobsters, seasons for sea cucumbers, and they have measurements and they are very regulated by the parks service.

Robyn Williams: Yes, I've been most impressed by the regulations and the thoroughness with which people from Ecuador keep out visitors carrying all sorts of seeds and rubbish that otherwise would be a problem. But nonetheless, many years ago people brought in rats, all sorts of nasty pests. Are they still there?

Monica Plaza: The rats, yes, I'm afraid they are. We have managed to clean some of the islands, like we have eliminated the pigs from Santiago, over 100,000 goats between the northern part of Isabela and Santiago islands. But the rats I would say it's impossible. We have managed to clean some little islands from rats, but the black rats were introduced when men came here in 1535, when the Spanish discovered the islands. They made an experiment with rats, not here, but it has been done outside, where a rat can stay afloat for two miles before they drown. So if the very old ships, the pirates, the Buccaneers, the whalers, of course they were on board and they just swum ashore.

Robyn Williams: And you said 100,000 goats?

Monica Plaza: Yes, we have eliminated over 100,000 goats from the northern part of Isabela and Santiago. It's a goat and pig free island now, Santiago. Unfortunately we still have the rats, and that's why we still have to breed tortoises, we still collect the eggs from there because otherwise the hatchlings would never survive due to the rats.

Robyn Williams: There are many islands with different kinds of tortoise, and very famously they found on one island poor old Lonesome George who…

Monica Plaza: He's passed away now.

Robyn Williams: He's passed away, yes, Attenborough had him on the television, and I think two weeks after he was filmed he passed away. He had been alone for how many years?

Monica Plaza: They estimated his age was probably 100 years, but alone, they found him in the '30s.

Robyn Williams: 50 years on his own, poor fella. Now, what is that? I'm looking out to my left out to sea about 300 metres. It looks like a feeding frenzy. What is it?

Monica Plaza: It is a feeding frenzy of Galapagos shearwaters, probably 300 of them. And I see a couple of Nazca boobies. They are all after probably a school of sardines or mullets right on the surface. Typical Galapagos sight.

Robyn Williams: I heard a story that some of the pelicans have a bird land on their back and wait until they regurgitate the fish from the pouch and this little bird steals the fish. Is that right?

Monica Plaza: Yes, that's the brown noddy tern, one of our endemic subspecies, and it's actually waiting for the living fish to escape from the pouch while the pelican is emptying the water out of the pouch, and then they can swallow the tiny mullets or sardines. And so some of them manage to escape from the beak, that's what the brown noddy is waiting for, for a live fish to come out from the beak pouch.

Robyn Williams: And so there is a brown pelican actually out sitting on the ocean. Does it mind having a bird sitting on its back?

Monica Plaza: It doesn't seem at all like he minds, he's just minding his business, emptying his pouch and swallowing. So whatever escapes, he can share.

Robyn Williams: Okay, thank you, and let's go to shore.

Monica Plaza: Okay, let's go.

Robyn Williams: And you're listening to The Science Show on Radio National, coming from the Galapagos Islands where we were just on Rábida Island, which is rust-red and quite large. All these islands differ in size, depending on when the volcano first erupted. And of course the tallest ones, the biggest ones are the most recent, the other ones have been worn down as the plate goes over the hot spot and new islands are formed, but the older ones get flatter and sometimes sink.

It was remarkable landing on Rábida Island, to see a sea lion who had just given birth, just minutes before we landed. There was the mother moving the young baby around, and the afterbirth lying next to her. And as we watched, a mockingbird came to eat some of the afterbirth, and the mother fussed, trying to get the baby away from the lapping water, higher up the shore. And it was quite incredible how the other sea lions came close and she shooed them away. Apparently the mother looks after the baby for two days with the secretions of very rich milk, and the baby grows, and then she goes off to sea to find some fish and feed it more. They look after their babies very well on Rábida Island.

Previously in Puerto Egas, on the island of Santiago which is also quite large, on shore a rather remarkable thing happened with one of the visitors who thought he'd discovered an albino marine iguana, and there it was on a piece of rock looking all white and its arms sticking out and the head rather stark. And so he took lots of photographs and boasted on the way back to one of the naturalists who said, 'Well, frankly, sorry to disappoint you but that wasn't an albino marine iguana, that was a skeleton you've just photographed.' Ah well.

On Isabela, the very large island, we had to cross the equator and come back south again, looping around. There were mangroves, huge mangroves, and Elizabeth Bay which is essentially turtle central. So many turtles there, and penguins. But three sets of turtles we saw were actually mating. There you had the female trying to keep the male up above her, carrying him. The mating took some hours, and meanwhile there's another male standing by to take over because the whole process takes an awful long time and apparently requires more than one male. Hours, yes hours. And one of the Canadian women, one of the tourists who watched, said, 'If it took that long with us, the population would crash to zero.' Oh well.

Next we go to a volcano, Darwin Volcano, to see what we can find.

David Inge: Good morning everybody, welcome. Welcome to Sullivan Bay, and then on the other side we have Bartolomé. This is a very beautiful island here. And then this morning in this visit here where we get to see the lava formation. So we get to see lava, and then lava, lava, lava and lava. Yes, because you see in this area, when we have these conditions, when there is no vegetation here, also there is no animals here. A few lava lizards, sometimes we have some snakes, we have a few finches as well, but very few species over here. One is a cactus. We have a different kind of cactus. One is a prickly pear cactus, and then also we have the lava cactus. The lava cactus is a very, very small species, so that one is endemic to the Galapagos, and also is endemic to the areas of very new lava, and we call them pioneer species, and one of these is tequila. So this is an endemic pioneer. This lava, when the age of this lava is just around 103 years old, so it's very new, really hard conditions. And there's no really good place for the species to survive around here. But some species are start making here.

Robyn Williams: So now I am walking over 100-year-old lava, and it's just stretching forever, there's great piles of it, like giant black cowpats, huge things, with, as David was saying, not one blade of grass, not one piece of wildlife apart from…ah, there's a lava lizard running in front of me. I wonder what he eats. It's probably bits of insect, if he can find any. And he's blending in quite wonderfully with the landscape.

And it looks not just like a landscape but a kind of black moonscape. Obviously this is one of the newer islands; if it's got active volcanoes obviously it has come out of the ocean quite recently. And surrounded by hills, all of them conical, which indicates that they must have been volcanic themselves. And off we trudge.

David Inge: You see a formation like in Hawaii. This is a volcanic and an oceanic island, so we have similar conditions. This is a volcanic ocean area, so yes, when the volcano starts to erupt here, so it starts to appear here, the islands. And then the name for the lava, the lava we call the Pahoehoe. Pahoehoe means flat lava or slippery lava, and also sometimes ropey lava. So that means Pahoehoe.

And then we have another kind of lava we call Aa [Ah-ah] lava, so that's a very sharp lava. We adopt this name probably for the Aa lava because if you walk barefoot on the lava it hurts your feet, so you say, 'Ah, ah ah!' So that is the name for this lava.

And all this lava is basalt, and then yes, in this basalt also we have many different minerals. So one of the minerals here, you see, is iron. So when we have the combination of the iron with the gas, with the water, so it changes the colours. So that's the reason you see on this lava, in some parts we have black, in another part we have the colour brown, and even in red, because there's more concentration of the iron and it produces a chemical process that changes the colour of this lava.

So they move very, very fast, so that means it's also very, very hot. It's over 1,200 degrees Celsius. So that's the two different kinds of lava we have here. So this Pahoehoe is very, very common in the whole of this area, you can observe it here in the rocks. But then also you've see under this lava we have another material here, we have ash, we have pyroclastic ash. So then also probably was water here, so they make big bubbles. So it's very, very interesting. Okay, let's continue.

Robyn Williams: David Inge. And it's quite extraordinary to see how some tiny spindles of plants are trying to establish themselves, some of them with tiny flowers, and apparently the finches come along and sample the flowers and of course take some seed with them and spread that way. But over there about 100 metres from where I'm standing is a bunch of cactus. It is really the most wonderfully brave thing. Somehow they are growing on what is virtual rock. They've established some sort of foothold, if you like, and pioneer species beginning to establish some kind of green life on this utterly black, hugely extensive lava landscape. That's how gradually life begins to form, succeeded by more and more different plants and eventually animals.

And one last thought as we leave this extraordinary landscape which seems so barren apart from the spindles of tiny plants and those brave cactuses clutched together, the only signs of life on what is really the most amazing reminder of the origin of the Galapagos Islands. And David stoops down and picks up a sliver of blue stuff. Now, what's a tiny bit of blue doing here? And he warns us, 'Well, that actually is rat poison.' Even here they are still trying to combat those appalling pests which first landed of course hundreds of years ago when the Spaniards came out with their ships and those hardy rats flew to shore. They're still trying to get rid of them, along with, as you heard, the hundreds of thousands of goats that were brought here and needed to be eliminated. Oh well, on we go.

And now to a situation of contrasts, the town on Isabela, where Darwin landed. And the place is absolutely packed with sea lions. In fact the water slides and the play area built for children is actually crammed full of sea lions. And the tube down which the children are supposed to float has actually got this great big half-tonne sea lion in it. Good evening. It's not very happy! It wants me to clear off. A great big mouthful of teeth.

Woman: We were told this is for children.

Robyn Williams: It's for children?

Woman: Yes, yes.

Robyn Williams: He seems very happy taking over. I wonder whether the kids get him out of the way. Mind you, they are probably sheltering from the rain.

Now I'm by the shore of San Cristobal, and on the shoreline we've got something like 150 sea lions just lounging around, a couple of them with offspring, and mockingbirds are wandering around having a bit of a feed. It's interesting that not only in the water park at San Cristobal (where the kids are supposed to be playing I suppose) that you have sea lions taking over, but most of the park benches; instead of tourists or locals sitting on the bench you've actually got sea lions. And he's one coming towards me now looking very friendly. You going to say something? Good evening. It's quite a young fellow, comparatively slim. No, he's going off again. I'm obviously not terribly exciting.

And finally here we've got a mother with offspring, almost the same size, desperately trying to get hold of a teat to suckle on. Yes, he's found it. And what it tastes like with all that sand getting in the way, I can't imagine. Meanwhile there's a brawl over there. How do you run a town when the population of sea lions is far greater than the population of people? Now we go on a little town bus up to the monument where Charles Darwin is commemorated.

Well, now we've walked away in San Cristobal, out of the way of those ferocious sea lions. No, they are quite pleasant really accept that they don't like their water slides and other territories infringed. High above the coastline and we can look down and see lots of rocks, and there's a bit of a quay there with three sea lions on it. And here in front of me is Charles Darwin with, suitably, a finch singing on top of his head.

We've come through great big stands of giant cactus, many of them with fairly soft spikes. The spikes don't have to be quite as tough when you don't have tortoises and land lizards, land iguanas chomping them, and so they can grow rather more sturdily. But they still retain their spikes and the spikes are soft. They need to be retained because they pick up water, and that's how the water balance of the plant is maintained, especially now in what is the beginning of the rainy season.

The statue of Darwin is very tall, about two and a half times the size of a real person, he's got great big hands. And he's looking out into the distance. He doesn't look like Darwin actually, quite a young man, a great big coat. He's holding a book called Galapagos in his hand.

Marvi Cordova: Charles Darwin, on this area of San Cristobal, Darwin did one of his stops on this part right here. He was able to collect many different species. Actually on the San Cristobal he collected one of the four types of mockingbirds that we have on the Galapagos. You have seen some of them on Isabela, for example, those are known as the Galapagos mockingbirds. The one that he collected from here is known as the Chatham mockingbird. Most of the islands have an English and a Spanish name. San Cristobal is the Spanish one, Chatham is the one for English, and it's due to the British colonies that we had at the beginning on this part here.

Now, for the whole trip that Darwin did on this area, we did a nice monument, he visited San Cristobal once again, which is known to be our capital on this part here. The statue, you see his hand is pointing to the back. This is the area where he actually landed. We have him actually going up to the highlands, he collected a couple of the birds, he got to see the giant land tortoises also on this part here. Remember the giant land tortoises are very famous all around the Galapagos. They do show a neat adaptation for their shells. Even though sometimes they might look very similar to us, their shells are actually different, depending on the areas where they live. Some of them would be adapted for lower vegetation, some of them will be adapted for higher vegetation. This is something that Charles Darwin did not notice when he came to this part here.

He was more interested in a couple of different things. In a couple of his diaries he wrote that he was very amazed by the landscape. You can see amazing views all over on this part here. So Charles Darwin was mainly paying attention to a lot of the geology of the islands most of the time on this part, and he was collecting a lot more of the species at the same time on this part here. So that was history right here for Darwin on San Cristobal. You can see him with all the animals on this part here, San Cristobal has always been well known for sea lions. You saw lots of them derived from many sea lions all over around the place. Actually the rock wall was built to protect the town from the sea lions because they were walking all over around the town. Sea lions are very nice, but if they leave their droppings on your door, that's not nice at all, right?

My name is Marvi Cordova.

Robyn Williams: Marvi Cordova. And you're a naturalist?

Marvi Cordova: Yes, I'm a naturalist right here on the Galapagos.

Robyn Williams: Tell me, how well do the Ecuadorian people regard Charles Darwin? You know, he's famous here, there is a statue here, but throughout Ecuador do they think he's a hero?

Marvi Cordova: I don't really think so, no. Most people usually on Ecuador don't really know that much about what is nature on the islands, things like that, everybody thinks that Galapagos is a park because we have special laws especially from the UNESCO program that protects the islands, so not everybody is allowed to live here. Not really that many people on Ecuador know that much about the islands, and I'm pretty sure they don't know that much about Charles Darwin. Most of them might hear a little bit, a small piece of him during maybe, I don't know, science, in one of the classes, and a little bit more about evolution, but that will be it, not that much. On Galapagos he's pretty big. He basically put us on the map, so he's very famous on this part here.

Robyn Williams: Yes indeed, and he was saying before that you don't have land iguanas or tortoises here at San Cristobal. What happened to them?

Marvi Cordova: Not on this part. On the area where we are walking we don't have them. What happens on this part here is when we had the first colony in the 1820s, the gentleman who was in charge of this whole colony right here, Manuel J Cobos, he killed most of them. He built a big industry for the meat and the oil, so he was making a lot of money with that, plus he was harvesting sugarcane also on this part here. So he wiped the whole part of this island from land tortoises and land iguanas.

Robyn Williams: Yes, they were pretty convenient, these giant tortoises, you could stick them on a ship and store the meat and open them whenever you felt like it a few weeks later out to sea.

Marvi Cordova: That is true. It has been said actually that a lot of the whalers who sailed to the Galapagos, they had wrote on their logs about the lifespan of the land tortoises without their food and water, that's why they took so many of them, it is estimated that they can live over a year. There are a few stories for some of them that they claim that the land tortoises can live over two years actually without their food and water.

Robyn Williams: Two years without food and water? That's incredible!

Marvi Cordova: Yes. Well, it has to do also with their system. They have this…it might be like a defence for them, getting them ready for when seasons are very bad for them, this reptile has to have very drastic adaptations. They can store fat on their bodies which then later can be turned into liquids to survive. You have seen the islands of this part here, very barren lava, no water whatsoever, so they must have very drastic adaptations, right?

Robyn Williams: Thank you Marvi.

Marvi Cordova: My pleasure sir.

Robyn Williams: And my naturalist friend tells me that it was in fact guano, those great big white patches you see on rocks all around here that's obviously bird poo, lashings of it, that is the secret that turned Ecuador, the president way back in the 1820s, towards actually having the Galapagos as part of this state, because otherwise they thought, well, it's a bunch of old islands and a few wild creatures on them but of no great account, but guano could be something extremely valuable. Unfortunately, unlike in other parts of the world, the guano turned out to be fairly thin and didn't produce the kind of industry that necessarily might have been in the president's mind. But the Galapagos became therefore part of Ecuador. A faeces origin, if you like.

Now I'm on the tiny island of North Seymour, and what a contrast. The sun is beating down, the trees are quite low and grey and leafless. Sea lions everywhere, in fact we couldn't get off the boat because sea lions were getting in the way. Some young ones, some older ones, and some of them just lying there looking at me, indolent. And all around here you have gigantic birds, frigate birds, the great frigate bird and the marvellous frigate bird, one with a red patch under its chin if it's a male, which then inflates into a great big balloon. You may have seen it on television, you may have seen it in David Attenborough's series.

And…oh gosh, a finch has just landed in front of me, one of those ground finches that fascinated Darwin so much. But all around you've got these nests either at waist level or at eye level, and in each nest you've got the juveniles of these frigate birds. I must tell you, the adult ones have got a wingspan of something like seven feet or nearly two metres. They are gigantic birds. And apparently the youngsters sit there in the nest for about 10 months being fed. And some of them, the young ones, are very, very fluffy indeed with their white feathers, and they turn their white feathers to the sun so that they can actually cool, and they pant a bit to keep their temperatures down. It is very, very hot, and one wonders how they can survive without either shade or terribly much water. Apparently the water comes from the cactuses which they peck at.

And there in front of me is not just one of those marine iguanas but a land iguana, which is a different colour. It's the size of a very large cat, and sort of ginger of that kind of colour as well, with a great big smile. Apparently they chomp cactuses for a living and they are quite indolent…this one is moving quite slowly across my path.

And further in the distance you have along the coastline lots of blue-footed boobies whose nests are on the ground. And being completely free of predators, they can take that kind of risk, and they, again, look after their youngsters for quite some time until, having shed a bit of weight and a few of their juvenile feathers, they can then take off and start fishing themselves.

It really is the most huge rookery, hundreds upon hundreds of these giant birds in nests, up if they are frigate birds, at about waist level or on the ground if they are boobies. Hundreds of these birds, calling. The males of the frigates doing a bit of a dance, waving their wings for the females to take interest, and all completely protected from any kind of prey, which is why their numbers are so gigantic and they have been able to evolve so incredibly quickly to adapt to these particular, different, special conditions here out in the Galapagos.

And now meet Pepe. Pepe looks very well fed. He's lying here in the rain, great big fat neck, chomping away at leaves. His front legs are quite stout, huge shell, as you can imagine, I imagine he weighs a third of a tonne, but who can tell, I'm not going to lift him! Pepe, to introduce you properly, is a giant tortoise, and he was given his name by the first trustees of the Agama family who took care of him up to 18 years of age when, by agreement with Monsignor Hugolino Cerasuolo Stacey, third prefect of the current apostolic vicariate of Galapagos, materialised the move to his facilities in 1967 becoming the 'First Missionary' in the islands.

This reptile whose age and accurate origin is unknown, is presumed to be from San Cristobal Island, and estimated that he is about 63 years old. I think he looks more like 70. He is currently is part of the breeding program managed by the Galapagos National Park in order to improve the status of the population of island tortoises.

He's looking off to my right now, and serenely surveying his solitary empire, and obviously in absolutely flourishing good health. Now let's go and see some of the offspring he may have given rise to.

Well, that was lonesome Pepe. And you're listening to The Science Show on RN. And I'm walking up a red track through a kind of forest of 100-year-old very large cactus plants. They are just about the same age as the tortoises I'm about to see, which can live to 100, 150 years. And I’m with a naturalist called William who is about to introduce us to some of these creatures which have been bred to make up for the fact that many of them became extinct on certain islands. And now you can repopulate parts of the Galapagos with these marvellous huge creatures.

William Cox: Let me tell you first this building here was the original tortoise release centre. It has been actually afforded by the San Diego Zoo. They started back in the 1960s. And this is a conservation program that conserves the incubation, you know, the artificial incubation of the tortoises here, they have some incubators because in the wild they are exposed to the predators. And there is a very low survival rate in the wild of these species, so that's why they have started this conservation program, bringing in the first eggs of some tortoises from the islands in the mid-1960s.

They had a couple of incubators in there, and afterwards what they do is to raise the little ones until they grow big enough to be repatriated. They send them back to their original islands. They make sure tortoises are sent back to the islands where they belong to by marking them here. So this is in short what they are doing here to try to redress the balance, because the tortoises have been actually wiped out of the islands by the whalers, other sailors in past centuries, and nowadays we are trying to repopulate the islands with the baby tortoises. So please, let's go there and take a look at the baby tortoises first. They have the baby tortoises in each one of these pens.

Robyn Williams: They are tiny, aren't they.

William Cox: They are, they are like miniature giant tortoise. They have several of these pens all over the place, if you take a look over there, they have actually almost 1,000 baby tortoises right now here in the Darwin Station. And as I said before, they started back in the mid-1960s bringing the first tortoise eggs from Pinzón Island. And obviously they had to improve a lot of this activity. It was, after all, the first time somebody was doing this kind of conservation program, so at first they had to experiment several times. They didn't have a very high successful hatching rate. But nowadays after about 50 years they have improved a lot. It is over 88%, the hatching success rate.

Well, the incubators are in a little building that you are going to see later, and after they hatch out they bring the little baby tortoises from their boxes to simulate what happens in the wild. And then after a couple of weeks they bring them here. So the ones you see here actually are the youngest baby tortoises. Some of them are youngest and oldest, look at the sign for instance, these are from Santiago Island, they were born last year, 2013, so some of them are not even one-year-old.

The little ones will be in these little pens for the first two years because when they are newly hatched the baby tortoises are very small and vulnerable. They are soft-shelled, so they could be an easy prey for any kind of predator like a rat for instance or a cat or whatever else is wandering on the islands. That's why they protect them here with this mesh wire, especially at night, to prevent these predators.

But they will open up of course later on this cover. But notice inside the pens, I repeat, there are the little ones, for the first two years they live inside the pens. And after two years they release them in the open corral down there where you can see some other ones which are a little bigger. Notice also that they carry a number on their shell…

Robyn Williams: Yes, they are in fact about twice the size of your spread hand. So pretty small. There is no indication as you just look at them that they are going to be these giant creatures weighing a third of a tonne or more.

William Cox: As you can see down there, each one of these corrals or pens have a pond which they fill with water obviously to provide the tortoises some water to drink or to cool off. The tortoises carry numbers of different colours on their shell because they belong to several islands, so in this way they identify the baby tortoises. While they are here they are going to carry this number on their shell. It's either blue or yellow or white according to the island they belong to, say Pinzón Island, Santa Cruz, Española, Santiago Island. In this station they have tortoises from all of these islands, four islands.

And after two or three more years that they are adapting gradually to the natural environment here, they are going to be ready to be released back in the wild. But what they are going to do just before they release them on the islands, the baby tortoises, they inject a microchip on their hind legs. This way they are going to keep a track on their activity on the islands. The chip is going to be there for a long time and they have those devices like the GPS, and they go back to the islands from time to time to check it out.

We know that they are doing very well since this repatriation program started back in the mid-1960s. They have repatriated up to 4,800 or so tortoises, nearly 5,000 baby tortoises actually. They mostly have been sent back to Española Island. On Española Island nearly 2,000 tortoises have been repatriated. And the program is still going on because the status of these animals is endangered, it's an endangered species. So we need to recover the number of tortoises because they were recently abundant back in time. You know, when the islands were just discovered by the Spaniards there were probably over 300,000 of them on the islands. But due to the activities of those sailors, such as pirates, whalers and the like, actually more than 90% of them were taken away.

The census they made back in the 1960s showed that only 15,000 tortoises remained in the whole archipelago. But nowadays they are over 20,000 or 25,000, considering the repatriated ones and considering they have been also breeding back in the wild and they are nowadays protected because, well, the islands became a national park.

Robyn Williams: William Cox, naturalist, talking about some of the marvellous research being done on conserving the tortoises, which of course are fairly leisurely about their reproduction rate, they are not rushing to have sex.

William Cox: Okay, from this place you get to see a little bit down there, so I'm going to tell you how the tortoises actually breed. You know, the male is usually bigger, at least twice bigger than the females. So he is going to chase the female. So in the breeding season, which is starting right now, whenever he is closer to her, he is going to push her against a wall, against a tree or whatever and then he mounts her from behind. The male has a concave shape underneath to fit on the upper shell of the female, and also a long tail where his penis is located, underneath the tail, and this way they make sexual contact. And afterwards the female is going to lay the eggs some three or more weeks later. But they would be able to keep inside their shell the sperm there for a longer time. So they will decide when to lay eggs.

But whenever they lay eggs what they do is to dig in the ground a small pit. The eggs are, by the way, like tennis balls, bigger than the sea turtle eggs which are rather like ping-pong balls. Once she is done she is going to cover the nest with dirt. And then she urinates on top and then she leaves. Why do you think she urinates on top? It's because later it's going to make a thick paste with the dirt in order to protect the eggs, otherwise she is never going to see the eggs again. She is not going to see the hatchlings either because, as I said before, they are independent from the very moment they emerge out of the nesting area.

Then it's going to take about 120 to 150 days before the baby tortoises emerge from the nest. Once they break the eggshell underground the baby tortoises do not come out immediately. They'd rather spend some time underground, and meanwhile they feed on the yolk that remains attached to their plastron which is very nutritious. And it takes usually at least a couple of weeks, this process. And only after that they come up to the surface.

So in order to simulate what happens in the wild, they do about the same here. After they hatch from the incubators they bring them to the dark boxes where they spend a couple of weeks or so, and then they go to the pens you have seen back there.

Now, they have got two integrators there. What for? According to the scientific research, the sex of an embryo is determined by the temperature in the nest. So the parents' chromosomes have nothing to do with it. So we know that at higher temperatures we have females, and at lower temperatures we have males.

Robyn Williams: Typical.

William Cox: Typical. That's why we have two incubators there. And what are we trying to get more? Males or females? Obviously females, more females, actually 75% of the eggs will go to the incubator with the higher temperature to get more females. In this way there's going to be more chance to perpetuate the species. So this is how it is working.

Robyn Williams: William Cox, who is a naturalist, attached to the Darwin Centre. He tells me that Galapagos actually means 'saddleback', which describes one form of the tortoises' shell, one that is kind of arched in the front to enable the tortoise to reach up, as you may have seen in David Attenborough's marvellous three-part series, so the tortoise can reach up and gobble the flowers of the cactus which is otherwise too high if you've got a normal shell. A normal shell of course allows you to barge through the undergrowth, like most of the Galápagos tortoises do. They release them after breeding them here at about the age of four or five when the shell has hardened, and that way they are not in any way vulnerable still to the predators such as the Galápagos hawk which can otherwise zoom down and gobble up the youngster.

And now we are reaching a very special enclosure.

William Cox: Okay ladies and gentlemen, this is the place where Lonesome George was living for the last 20 years. He was found on Pinta Island back in the early 1970s, actually in December 1971. He became suddenly news worldwide because they thought the tortoise had been gone from that island a long time ago. So here was the last representative of the Pinta tortoise species. And they named this tortoise appropriately Lonesome George.

In February 1972 they transported the tortoise from Pinta Island to Santa Cruz to take care of him here in these facilities. They wanted to find another one desperately, so they organised several expeditions to go back to Pinta Island, and they surveyed the island in order to look for a female to make sure the perpetuation of the species. The idea was to bring the female and to release her here with him in the same corral to encourage them to reproduce, and descendants would be repatriated later on back to Pinta Island to repopulate the tortoise population on that island.

Well, the thing is that Lonesome George was isolated from the rest of the tortoises here on the station by the waterfront down there. Actually the first 20 years he has spent down there. Later on because of the advice of a herpetologist, they built a new corral to provide him more space and to let visitors to him because he became a celebrity worldwide, seeing as they did an advertisement offering $10,000 reward after they failed in finding a female tortoise on the island of Pinta.

So even though it gave no result and George was still solitary, a lonesome one. So he spent the next 20 years of his life down here in this corral. In 1992 they added a couple of female tortoises down there. These tortoises were taken from another island because on Pinta they were gone. They made DNA research and established a couple of female tortoises from Wolf Volcano on Isabela Island were likely to match. So they put them down there to see what happens. And guess what happened?

Robyn Williams: Nothing.

William Cox: Exactly. Apparently nothing.

Robyn Williams: Well, you'd forget after 20 years, wouldn't you?

William Cox: Well, there are several hypotheses about his behaviour. They say that probably he never interacted with the female tortoises on his island because he grew up alone, so probably he never met them, he never learned. Or probably he was too old. And some say other things as well.

Robyn Williams: He couldn't have been gay.

William Cox: Yes, that's what they say.

Robyn Williams: A gay giant tortoise? Who'd have thought! But as you look into the next enclosure, another story, there's Diego, aged 150, still performing, as his two female companions can confirm. More on that next week. My thanks to William Cox at the Darwin Research Centre, and all the other naturalists on the Galapagos Islands. Production by David Fisher. I'm Robyn Williams.

Wendy Regan :

William Clarke-Hannaford :

17 Jun 2014 11:48:15am

Thank you for that fascinating insight into the life on the Galapagos Islands. Such a significant place in terms of endemic animal species and also it's importance in the history of science. Was great to hear about the effort and success of the tortoise breeding program there and the sea lion's bark in the playground was impressive to hear. Would be wonderful to visit there, in particular see the marine iguana.